Addressing Power Grid Stability With Grid-Forming Converters in Future Energy Systems

Synchronous generators (SGs) have been a major component of the power system's historical reliance on inertia and grid stability. However, since there is a visible lack of inertia with the growing integration of power-electronics-interfaced clean energy sources, the grid's stability has faced issues during the last ten years. Now, grid-following (GFL) converters are mostly used on the presumption that inertial stimuli are enough to control system stability. However, this assumption turns out to be insufficient for the future low-inertia grids that are projected. Grid-forming (GFM) converters, which emulate the functions of conventional synchronous machinery, have emerged as a possible approach to overcome these issues and enable low-inertia grids. Although the literature provides information on small-signal instability performance study of GFM converters, large-signal instability research is still lacking. Moreover, a multitude of topologies and variations of GFM conversion have been put forward; nevertheless, a thorough comparative analysis that encompasses all GFC variants and specifically addresses large-signal stability concerns is noticeably lacking. By consolidating and contrasting all currently available GFM control techniques from the perspective of large-signal stability concerns, this work aims to close this gap. The goal is to set the stage for further study and development of GFM mode converters designed particularly for large-signal stability analysis and stabilization in the next low-inertia grids. This thorough analysis not only resolves the existing shortcomings that have been highlighted but also lays the groundwork for furthering our knowledge of and use of GFM conversions in the dynamic world of power systems.